The invention relates to a cutting device, in particular, a lawn mower having at least one rotating knife, which is mounted on a rotating, motor-driven knife carrier by a screwless, detachable connection, the connection being detachable by a relative rotation between the knife and the knife carrier.
In lawn mowers it is necessary to regrind the knives from time to time to ensure a smooth, clean cut of the grass. When the knives are mounted, this regrinding is only possible temporarily. Usually, the knives are removed and clamped in a special grinding device to maintain the correct cutting angle over the length of the knife.
After a longer period of use, conventional screw connections for the knife are clogged with cut material and soil, so that it becomes more difficult to detach the knife. Thus, a screwless knife carrier is already known from German patent DE 195 20 618, having the features described at the outset, in which the knives can be exchanged without the use of tools.
This known knife holder comprises a motor-driven disk, which supports two downwardly protruding pins, a knife being placed on each of their projecting ends, so that each knife is swivel-mounted on its respective pin. Below the knives a rotatable plate is located, which has grooves each extending in a peripheral direction in the area of the pins, so that the plate can be turned relative to the disk with the pins and the knives. The plate thereby accommodates the ends of the pins in their respective grooves and supports the knives from the bottom in a screwed-in position. To secure the plate in its screwed in position holding the knives, each groove terminates in a recess in which the associated pin engages. This locking connection hinders the plate from turning back. However, it cannot preclude this turning back when the plate is loaded by random outer influences in a direction of release.
Moreover, the rotatable plate requires a support from the bottom. This support is provided by a cap arranged underneath. This cap covers the rotatable plate and, as a result, makes accessibility of the plate more difficult when the knives are to be removed.